Practice Quiz-Lecture 2 Flashcards
Rutgers School of Public Health decided to study carpal tunnel syndrome (CTS) in grocery store workers in New Jersey’s Essex and Morris counties. Public Health researchers recruited 30 grocery store workers from Essex County and 20 grocery store workers from Morris county and recorded the number of repetitive tasks that workers performed using muscles in their hands and wrists. Researchers also assigned a CTS risk score of 1, 2 or 3 to each worker, where 1 = low risk, 2 = medium risk and 3 = high risk. Define the population and the sample
Population: Grocery store workers in Essex and Morris counties in New Jersey. Sample: 50 grocery store workers from Essex and Morris counties.
Rutgers School of Public Health decided to study carpal tunnel syndrome (CTS) in grocery store workers in New Jersey’s Essex and Morris counties. Public Health researchers recruited 30 grocery store workers from Essex County and 20 grocery store workers from Morris county and recorded the number of repetitive tasks that workers performed using muscles in their hands and wrists. Researchers also assigned a CTS risk score of 1, 2 or 3 to each worker, where 1 = low risk, 2 = medium risk and 3 = high risk. What type of variables are CTS risk score and the amount of repetitive tasks?
CTS risk score = categorical (or ordinal); Amount of repetitive tasks = continuous
Rutgers School of Public Health decided to study carpal tunnel syndrome (CTS) in grocery store workers in New Jersey’s Essex and Morris counties. Public Health researchers recruited 30 grocery store workers from Essex County and 20 grocery store workers from Morris county and recorded the number of repetitive tasks that workers performed using muscles in their hands and wrists. Researchers also assigned a CTS risk score of 1, 2 or 3 to each worker, where 1 = low risk, 2 = medium risk and 3 = high risk. When drawing a bar plot to visualize the variable county, what will be your y-axis (i.e., vertical axis)?
Frequency or relative frequency of grocery store workers recruited from each county
Chronic traumatic encephalopathy (CTE) is a progressive degenerative disease found in people who have suffered severe blows to the head, including American football players. In a study of CTE in professional football players, researchers obtained information on age of the players, number of years they have been playing football, and used a cognitive test for memory loss to classify each player’s CTE risk profile as high or low.
Means and standard deviations are good ways to summarize CTE risk profile.
FALSE
The standard deviation of age is 9. The variance is:
81
In the example of CTE in American football players, age can be visualized using:
Histogram or box and whiskers plot
Suppose the 3rd quartile of age is 32 years. The proportion of players whose age exceeds 32 years is:
25%
A normal distribution is:
Symmetric
Height of children attending kindergarten in New Jersey’s public school system has a normal distribution with mean 39 inches and standard deviation 2 inches. What proportion of kindergarten children in New Jersey’s public school system are under 39 inches tall?
50%
The variance of a standard normal distribution is:
1
Height of children attending kindergarten in New Jersey’s public school system has a normal distribution with mean 39 inches and standard deviation 2 inches. 68% of kindergarteners have height between:``
37 and 41 inches
The first quartile of a normal distribution with mean 0 and standard deviation 2 is -1.349. The proportion of data below -1.349 is:
25%
The 97.5th percentile of a standard normal distribution is 1.96. The proportion of data above 1.96 is:
2.5%
A “sampling distribution” could be used to describe the distribution of which of the following statistics? A: Mean, B: Median, C: Standard Deviation, D: Range
A
